This is our donor TJ prior...
This is our donor TJ prior to adding the axle upgrades. As you can see, the stock Rubicon wheels and 32-inch Goodyear MT/R tires leave much to be desired for serious trail work. The JKS J-Spec 4-inch short-arm suspension we installed back in May '08 will accommodate a 35-inch tire without issue, so we thought the axles should do the same.
Last month we showed you how to make a front Dana 30 survive with 35-inch tires on a trail TJ. This month we're continuing our coverage on stock axle survival tactics by beefing up a rear Dana 35 found under the same Jeep Wrangler.
The majority of failures on a Dana 35 axle relate to weak 27-spline C-clip-style axleshafts. The factory never intended for these shafts to last with larger than 33-inch tires. So it is no surprise that Superior Axle and Eaton teamed up to build a Super 35 kit that increases axle spline count to 30 and axleshafts made of a much tougher chromoly-alloy material. Coupled with Eaton's virtually indestructible Detroit Locker, these shafts are the hot setup for TJ owners with busted axle blues.
In addition to the added strength afforded by Superior's Super 35 kit, we thought it was a good time to address braking safety. Everyone knows it takes more brake force to stop a larger tire, but not everyone chooses to address the issue prior to adding bigger meats. Luckily, TeraFlex manufactures a complete rear disc-brake conversion kit that allows TJ owners with drum brakes to gain significant rear-end braking improvements via improved cooling. The configuration uses OEM-style parts, which makes it super easy to find pads later on down the road. This installation was performed by the capable hands of Dustin Chernoah, owner of DC Customs in Ukiah, California, a family owned and operated business that specializes in bolt-on Jeep modifications and custom fabrication.
This is the Super 35 kit from Superior axle. The kit includes either an ARB or Detroit Locker (your choice), left and right axleshafts with Timken roller bearings, seals, and Grade-8 thread-in wheel studs. We like the fact that these axles feature dual lug patterns and a protective DuraCoat finish to help resist corrosion and to maintain a smooth surface finish. Another nice feature of these shafts is the "rolled splines" which are known to be upwards of 35-percent stronger than cut splines found on other axles available today.
Superior also hooked us up with 4.88:1 gearing and a master install kit to ensure Dustin had all the necessary parts to perform the gear swap. Upon receiving these parts we immediately sent the gearset out to Cryo Science of Oceanside, California, to have a cryogen treatment process performed on them. This process should remove any microscopic fractures in the metal and provide a 100-percent gain in strength over stock. The reason for this is simple; with the stronger 30-spline chromoly axleshafts, the weak link would likely be the pinion gear. We don't want our donor Jeep stuck out on the trail with a hard-to-change gearset, so, increasing the gear strength should in theory move the weak link to the driveshaft U-joint-a much easier fix to deal with while on the trail.
This is the complete TeraFlex disc-brake conversion kit for the Jeep Dana 35 and 44 rear axles found under all TJs from '97 to '06. This kit is ideal for anyone wanting to increase braking performance both on and off pavement. Designed as a complete bolt-on upgrade, the kit provides an internal drum parking brake, which provides outstanding holding power when compared to other disc-brake conversions. The whole kit installs in about four hours and is recommendable for anyone running larger than stock tires. Be sure to order a pair of new emergency-brake cables separately for your particular application.
We used a genuine Lube Locker...
We used a genuine Lube Locker gasket because of its superior sealing technology. Once you try these, you probably won't ever use silicon sealant again. These reusable gaskets are packed with innovations that vastly increase sealing ability. Each gasket features a rubber-coated steel core that is lined on both sides with a special orange elastomer beading that seals the perimeter and each bolt hole. This arrangement virtually eliminates any possibility of a leaky differential, even if the cover smacks a rock and shifts slightly.
One noteworthy modification...
One noteworthy modification required by the disc-brake conversion is the shortening of the factory hard-steel brake lines. As seen here, Dustin used a double-flare tool to refit where the transition from steel to rubber was located on the axlehousing. If you don't have a flaring tool to complete this process, take the lines to your local brake shop to have it done for you. In a matter of minutes, these lines can be shortened. Be sure to mark where you want the new fittings prior to leaving the garage.
A pair of small metal brackets...
A pair of small metal brackets are included with the TeraFlex disc-brake conversion kit. They allow placement of the new transitions from hard-steel to flexible rubber lines. As shown here, a self tapper secures each bracket to the extra material of the lower coil bucket. This arrangement makes the process of changing brake pads super-easy because they allow the caliper to be removed from the disc without disconnecting any brake lines.